© 2008 the mcgraw-hill companies, inc. chapter 3 biological foundations of behavior
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The Nervous System Brain: Structure and Function Brain Damage and Plasticity Genetics, Evolution, and Behavior Application: Health and Wellness
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The Nervous System
Neuroscience and Neuroscientists
Characteristics of the nervous system: Complexity Integration Adaptability Electrochemical transmission
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The Nervous System: Pathways
Afferent Nerves Carry information spinal cord and brain
Efferent Nerves Carry information muscles
Reflex Arc: Afferent nerve Interneuron Efferent nerve
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The Nervous System: Divisions
Central nervous system (CNS) Brain and spinal cord
Peripheral nervous system (PNS) Somatic nervous system
Sensory nerves and muscular activity Autonomic nervous system – internal organs
Sympathetic nervous system – arouses Parasympathetic nervous system – calms
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Neurons: Structure
Brain: Approximately 100 billion neurons Glial Cells: Provide support and nutrition Specialized Cell Structure
Cell body Dendrites Axon Myelin sheath
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The Neural Impulse
Resting Potential Stable, negative charge of an inactive neuron
Action Potential Ion gates cause depolarization Brief, positive electrical charge: firing
All-or-None Principle Once initiated, it cannot be stopped
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Synapses and Neurotransmitters
Synaptic Transmission Neurochemical communication Action potential (electrical impulse) is
converted into a chemical signal Synapses
Space between terminal buttons and the receiving neuron’s cell body or dendrites
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Neurotransmitters
Neurotransmitters either excite or inhibit Acetylcholine
Muscle actions, learning, memory Alzheimer’s disease: ↓ Ach levels Nicotine: ↑ Ach levels
GABA – inhibitory functions Anxiety: ↓ GABA levels
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Neurotransmitters
Norepinephrine Stress and mania: ↑ Norepinephrine levels Depression: ↓ Norepinephrine levels Regulates sleep states in conjunction with ACh
Dopamine Stimulant drugs: ↑ Dopamine levels Parkinson’s disease: ↓ Dopamine levels
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Neurotransmitters
Serotonin Regulation of sleep, mood, attention, learning Depression: ↓ Serotonin levels Prozac ↑ Serotonin levels
Endorphins Endogenous (natural) opiates Mediate feelings of pleasure and pain
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Neurotransmitters
Oxytocin Both a hormone and a neurotransmitter Related to onset of lactation in new mothers Related to attachment / emotional bonds
Drugs and Neurotransmitters Agonist – mimics or enhances NT effects Antagonist – blocks effects of NT
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Studying the Brain
Lesioning Naturally occurring or induced
Staining Electrical Recording
Electroencephalogram (EEG) Single-unit recording Brain damage, sleep, epilepsy, happiness
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Brain: Structure and Function
Hindbrain, Midbrain, and Forebrain Hindbrain
Medulla – control breathing, regulate reflexes Cerebellum – movement, coordination Pons – sleep, arousal
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Brain: Structure and Function
Midbrain Reticular Formation
Stereotyped behavior patterns like walking Brain Stem
Alertness, breathing, heart rate, blood pressure
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Brain: Structure and Function
Forebrain (continued next slide) Limbic System – memory and emotion
Amygdala Emotional awareness and expression
Hippocampus Formation and storage of memories
Thalamus Relay station for much sensory information
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Brain: Structure and Function
Forebrain (continued) Basal Ganglia
Coordination of voluntary movements Hypothalamus
Eating, drinking, sexual behaviors Emotion, stress, reward
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Cerebral Cortex
Occipital Lobe – Vision Temporal Lobe – Hearing, language
processing, memory Frontal Lobe – Intelligence, personality,
voluntary muscles Parietal Lobe - Spatial location, attention,
motor control
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Somatosensory and Motor Cortex
Somatosensoy Cortex Located in the parietal lobe Processes info about body sensations
Motor Cortex Located in the frontal lobe Processes info about voluntary movements
Point-to-point Mapping
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Split-Brain Research
Corpus Callosum Large bundle of axons that connects the two
hemispheres of the brain Hemispheric Specialization of Function
Right hemisphere Spatial perception, visual recognition, emotion
Left hemisphere Verbal processing, speech, grammar
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Intersection: Happy Brains?
Happiness: Prefrontal Lobe Asymmetry Positive emotional responses
More left prefrontal lobe activity Negative emotional responses
More right prefrontal lobe activity
Caution: Correlational Research Mindfulness (Awareness) Meditation
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The Endocrine System
Set of glands that regulate the flow or hormones into the bloodstream
Relatively slow communication system Interconnected with the nervous system Pituitary, thyroid, parathyroid, adrenal
glands, pancreas, ovaries, testes
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Brain Damage and Plasticity
Recovery from brain damage depends on Age of the individual Extent of the damage
Repairing the damaged brain Collateral sprouting Substitution of function Neurogenesis Brain tissue implants
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Genetics and Behavior
Chromosomes, DNA, and Genes The Dominant-Recessive Genes Principle The Human Genome Project Behavior Genetics and Adoption Studies
Fraternal and identical twins
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Genes and the Environment
The “Nature versus Nurture” Debate Nature describes one’s genetic potential
Genotype – genetic heritage Nurture the expression of that potential
Phenotype – observable characteristics Both physical and psychological characteristics
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Application: Health and Wellness
Stressors – circumstances and events that threaten individuals and/or tax their coping abilities
Stress – our response to those stressors Effects of acute and chronic stress Cognitive restructuring and self-talk
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Chapter Summary
Discuss the nature and basic function of the nervous system.
Explain what neurons are and how they process information.
Identify the brain’s levels and structures and summarize the function of those structures.
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Chapter Summary
Identify the endocrine system and describe how it affects behavior.
Describe the brain’s capacity for recovery and repair.
Explain how genetics increases understanding of behavior.
Describe the role of the biological foundations of human psychology in the body’s stress response.
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Chapter Summary
The Nervous System Structure and function of the nervous systems Structure of a neruon Electrochemical communication Neurotransmitters and their effects
Brain: Structure and Function Brain imaging techniques Hindbrain, midbrain, forebrain Cerebral lobes and functions